The couple in the link below swear they took a snapshot of a ghost in Alcatraz.
No such thing! They are just for TVLand and the movies!
Just a media stunt for Alcatraz!
Look at Call of Duty Ghosts. No one actually sees a ghost and they went way off base with calling it that, just because a dog appears.
Also beware of Photoshop and stupid people.
I've always told people a ghost would have to come up and tap me on the shoulder, because I don't want to see them, that would be waaaaay to freaky.